-LRB- CNN -RRB- -- Shark attacks on humans were at the lowest levels in half a decade last year , and a Florida researcher says hard economic times may be to blame .

Fewer people in the water means less chance for sharks to attack , ichthyologist George Burgess says .

Sharks attacked 59 people in 2008 , the lowest number of attacks since 57 in 2003 , according to George Burgess , director of the International Shark Attack File , part of the Florida Museum of Natural History on the University of Florida campus in Gainesville .

There were 71 attacks in 2007 .

`` One ca n't help but think that the downturn in the economy played a part in it , '' Burgess said .

Fewer people , especially outside of the United States , have the resources to go to the beach , he said .

`` To have a shark attack , you have to have humans and sharks in the water at the same time , '' Burgess said . `` If you have a reduction in the number of people in the water , you 're going to have a reduction in the opportunities for people and sharks to get together . ''

`` We noticed similar declines during the recession that followed the events of 2001 , despite the fact that human populations continued to rise , '' the ichthyologist said .

Sharks killed four people in 2008 , Burgess said : one in California , one in Australia and two in Mexico .

Forty-one of the 59 attacks worldwide came in the United States , and 32 of those occurred in Florida .

Surfers accounted for 57 percent of shark attacks , swimmers and waders were the targets in 36 percent of the attacks , and divers the rest , he said .

Burgess said the U.S. tends to see more attacks because of a large number of surfers , who are a favorite target of sharks .

And neither the economy nor the attacks tend to keep American surfers from practicing their sport .

`` All they have to do is drive to the beach with the board and get into the water , and the rest is free , '' he said .

And while an attack may make them a bit more wary , he said , `` I 've yet to find a surfer who says he or she wo n't go back into the water after a bite or a nip . ''

When the economy improves , shark attack numbers are likely to go up again , according to Burgess , predicting the number of attacks in the next decade will surpass those of the past 10 years .

`` We 're putting so many people in the water that humans are dictating the shark attack situation , '' he said .

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Sharks attacked 59 people worldwide in 2008 , Florida researcher reports

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Four people killed by sharks last year

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Economic downturn means fewer people hitting beaches , researcher says

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Surfers account for 57 percent of shark attacks